# Draw parallels of a sphere with tikz

How to draw properly parallels of a sphere properly? The equator is ok:

\documentclass{article}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}
\fill[ball color=blue!20] (0,0) circle (1.5);
\draw [thick,dotted] plot [domain=0:pi] ({1.5*cos(\x r)},{0.2*sin(\x r)},0);
\draw [thick] plot [domain=pi:2*pi] ({1.5*cos(\x r)},{0.2*sin(\x r)},0);
\end{tikzpicture}
\end{document}


Yet the other parallels are tricky to put in place.

This is one way to do it:

\documentclass{article}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}
\fill[ball color=blue!20] (0,0) circle (1.5 cm);
\newcommand\latitude{%
\draw (#1:1.5) arc (0:-180:{1.5*cos(#1)} and {0.2*cos(#1)});
\draw[dashed] (#1:1.5) arc (0:180:{1.5*cos(#1)} and {0.2*cos(#1)});
}
\latitude{30};
\latitude{0};
\latitude{-30};
\end{tikzpicture}
\end{document} It can be improved, by making the radius(1.5 and 0.2) variables.

You can use package tikz-3dplot-circleofsphere at here

\documentclass[tikz,border=1mm, 12 pt]{standalone}
\usepackage{tikz-3dplot-circleofsphere}
\begin{document}
\def\r{3}
\tdplotsetmaincoords{60}{125}
\begin{tikzpicture}[tdplot_main_coords]
\begin{scope}
\fill[ball color=blue!20,tdplot_screen_coords] (0,0,0) circle (\r);
\tdplotCsDrawLatCircle{\r}{0}
\end{scope}
\foreach  \a in {-75,-60,...,75}
\tdplotCsDrawLatCircle[tdplotCsFront/.style={black}]{\r}{\a};
\end{tikzpicture}
\end{document} 